Variable speed commutation and control of AC (Alternating Current) electric motors has had high interest and visibility for a number of years. It is well known that in most instances machines, systems and devices powered by electric motors with a fixed operating speed become more efficient, capable and effective when given an ability to vary the motor's operating speed. There are a number of techniques, methods and apparatus to achieve changing motor speed and the speed of the machines they power. Many of these systems use digital control methods to effect the proper power, commutation and speed. An example of a digital control method illustrated in FIGS. 1A-D illustrates a technique called Pulse Width Modulation or PWM. This common digital approach uses variable width digital pulse switching of a high frequency carrier wave to create a pseudo average voltage or current power level by summing (integrating) the on and off times of a given signal.
Normally any given analog electric motor converts incoming analog electric power into analog mechanical output power. But as can be seen in FIGS. 1A-D for a typical digital or PWM approach this is not the case. As illustrated in the series of FIGS. 1A, 1B, 1C, 1D; the incoming fixed analog AC power signal is converted into a fixed DC (Direct Current) power supply signal (FIG. 1B) which in turn is converted into a switching digital power signal (FIG. 1C) which is sent to an analog electric motor FIG. 1D. The goal of a PWM or digital controller is to provide variable or adjustable electric power to an electric motor to vary or adjust its mechanical power out. But to become a signal that can power an analog electric motor the electric signal input to the motor must become an analog power signal before it can power a motor.
FIG. 1C illustrates a typical PWM output signal typically sent to drive a motor. As can be seen the commutation signals barely resemble a sine wave, analog signal or any other analog motor power commutation signal. To create or change this PWM power into a motor useable power signal (FIG. 1D) either the motor itself or some type of very intense pre-motor filter must absorb, integrate, sum and smooth the PWM switched power signal before the motor can use it. In essence the digital power signal (FIG. 1C) must be converted into an analog power signal (FIG. 1D) so the motor can in turn convert the electrical power into mechanical power.
In most cases of other PWM or digitally electrically powered systems and devices there is a similar series of power conversion steps that must occur before the analog work output can occur. From light bulbs to huge electric furnaces if they are varied by digital or PWM means the electric power must go through some similar series of power conversion to be converted into useable analog light, heat, rotation, motion etc.
This digital to analog mismatch and rematch adds cost, complexity, losses and many others. Programmable analog control of power conversions provides an alternative path and/or complementary technology for digital control solutions.
The implementation cost and complexity are clearly hindrances to using most digital methods, as illustrated in FIGS. 1A-D. However, harmonic noise and interference power signals of the digital carrier signal is another undesirable circumstance that is seen by the motor (FIG. 1D), the power driver (FIG. 1C) and the power supply (FIG. 1B) and the AC grid (FIG. 1A). These interference signals of the digital carrier signal are definitely not desired, useable or favorable for any of the four systems affected by them. In point of fact these harmonic interference signals as well as other high speed digital switching power problems can often cause more system problems to the machines they power than the value of the improvements being sought in varying or controlling analog power using digital power.
Some of these very serious digital power switching issues can be overcome by implementing some type of power filters or signal smoothers in the power control circuit but these not only add more cost and components they also have energy loss issues, heating and performance limits. Others have tried to solve some of these very serious digital power switching issues by implementing forms of analog control and analog power solutions, as illustrated in FIGS. 2A-C [Need detailed Description of the FIGS. 2A-C including a discussion of the inefficient power factor]. Besides much higher expense, these traditional analog power amplification methods and apparatus that allow some measure of repeatable system control are usually very inefficient, costly and cumbersome.
However, PWM harmonics, overshoot, and resonance may not be the issues that they presently appear in practice. These aspects of digital control may simply be out of sync with the needs of the analog power devices they are driving. More specifically, if these signal characteristics are appropriately modeled and controlled by a complementary control technology then they may be used constructively rather than destructively in overall system design.
Optical & Graphical Programmed Analog Controllers
An alternative to these above traditional controller techniques have been disclosed and described in prior art patents U.S. Pat. Nos. 5,665,965; 6,087,654 and 7,797,080. These disclose methods and apparatus for commutating, controlling and powering electric motors and machines using Optical and Graphical Programming and Processing (OP/GP) techniques. FIGS. 3-5 illustrate some examples of the apparatus, methods and systems for this prior art and patent references in providing a simple but powerful closed loop control scheme for electric motors, machines and devices. A brief preview is illustrated of this prior art in FIGS. 3-5. These Figures illustrate, describe and note low power inputs of signals, sensors, vectors, parameters and variables to high power signals, programs, vector and commutation output are achieved using new analog techniques that use optoelectronics in new and innovative ways.
Specifically, a newer type of parallel analog processing and programming has been previously disclosed in the aforementioned patents is an alternative and complementary technology to serial digital processing and programming methods. FIG. 3A gives a general overview and basic side by side comparison of a traditional digital approach to computation, programming and power output versus an OP/GP approach to these same objectives. FIG. 3A lists a series of step by step I/O (input/output) of data capture and input; data program & process; program execution and output; and signal type, nature and use. FIG. 3B goes into some added detail for the programming aspects of the two approaches and gives an example of system programming using digital application software “C” programming versus Analog “Graphical Programming”. It is this technology and distinct method and application differences that make possible the present disclosure and serve as the basis and foundation for the present disclosure.
FIG. 4 shows additional details on the operation of opto-processors and opto-programming. The elements of an opto-processor include: 1) a first electro-converter to move from the electrical domain into a wave domain in which the signal content (including data and vector information) can be manipulated by an analog transformation, 2) a means making the analog transformation(s) that embodies the opto-program, and 3) a second electro-converter to receive the transformed wave signal and convert it back to the electrical domain. In FIG. 4A, the opto-processor is implemented with a series of electro-optical elements, LD, an light emitting diode to convert into the optical wave domain, a vector graphic wave aperture, OP, to perform that programmed transformation, and a photo transistor PT to convert the transformed optical wave back to an electrical signal. Input signal IS gets (EC) converted by LD into WS; which gets transformed or Opto Programmed by OP; which converts and outputs OWS1; which becomes the input to OP2; which further transforms, alters and combines e.g. co-programs OWS1; and then OP2 outputs OWS2; which becomes the input to PT; which now (EC) converts and outputs the resultant of OWS2 as a composite, controlled, variable programmed electric signal. An electrical signal (IS) is received, converted into a wave signal (WS), passes through one optical program feature (OP1) to be transformed into a first opto-programmed wave signal (OWS1), passes through a second optical program feature (OP2) to be further transformed into a second opto-programmed wave signal (OWS2), and is then converted into an output electrical signal (OS) with the desired programmed output signal parameters. Note that the output electrical signal may retain original input signal data, vector, or power characteristics in addition to the desired opto-programmed parameters. It is a very basic example of an OPP: where OP1 rotates moves graphic apertures (vector windows) that convolve (integrate) WS into an output wave OWS1 that then mixes, transforms with a non-rotating co-designed OP2 graphic vector aperture, to create and output OWS2; which contains new signal data in a wave domain that gets converted (EC) via PT into new signal data in an electric domain. Rotating, moving an OP in a wave field WS is a primary changing variable that directly creates, programs, controls, changes or alters the output electric signal OS. Changing the amplitude or bias of LD or PT also changes (controls) the output signal. FIG. 4B is a much more sophisticated embodiment of two OPP paths with both rotating and non-rotating Ops. This illustrates how complex integrated array signal processing and data storage is achievable using basic OPP technology. It shows multiple, concurrent, parallel input signals (IS) & programs (OP) can provide: parallel, signal, vector, matrix, and data processing & programming, with active and passive memory storage and buffering (OP), resulting in controlled variable interconnected or multi-dimensional outputs (OS). Not the same multi-dimensional opto-program is being applied simultaneously to independent input/output signal paths. Increasingly complex combinations of multiple inputs, outputs, and opto-program features enable a wide variety of applications in signal processing and resulting control algorithms.